Effect of orchard soil-management practices at different levels of nitrogen on nutrient availability and uptake by plum (Prunus salicina)

A field experiment was conducted during 1994-2001 at Bajaura, to study the effect of 5 orchard soil-management practices (clean cultivation, herbicide, green-manuring, intercropping, mulching + herbicide) and 4 levels of nitrogen (200 g, 400 g, 600 g and 400 g, half applied as calcium ammonium nitrate and half as farmyard manure per plant) on 6-year-old 'Santa Rosa' plum (Prunus salicina Lindl.). The highest leaf N (2.61%), Cu (12.2 ppm) and Zn (19.7 ppm) were observed with herbieide. The P and K were the highest (0.20 and 2.7%) with mulching with herbicide The lowest N, P and K (2.47, 0.16, 2.24%) were observed under intercropping with soybean [Glycine max (L.) Merr.]. Increasing the level of nitrogen increased the leaf N, P, K and Mn. The treatment combination herbicide with 600 g N/tree resulted in the highest leaf N (2.78%), and the lowest leaf N (2.44%) was observed with clean cultivation with 400 g N/tree (half N applied as farmyard manure). The highest leaf P (0.21%) was recorded with mulching + herbicide with 400 g N/tree (half applied as farmyard manure). The highest available soil N (81.3 ppm) was observed under green-manuring with cowpea [Vigna unguiculata (L.) Walp], available P (82.3 ppm) and K (306.3 ppm), exchangeable Ca (2 651 ppm) and Mg (3 908 ppm) with mulching + herbieide. Increasing the level ofN increased the available soil N, P, Fe and Zn content. Herbicide with 600 g N/tree resulted in the highest available N (89.3 ppm) and Mn (64.6 ppm) content of the soil. Available K (365 ppm) and Zn (3.38 ppm), exchangeable Ca (3 341 ppm) and Mg (4 302 ppm) were the highest with mulching + herbicide with 400 g N/tree (half applied as farmyard manure). Herbicide or mulching + herbicide resulted in a better nutrition of the tree.